R/V Knorr Athena metadata file Sun 16/Feb/2003 02:01:45 12kHz depth ( Depth12) Format: Depth (meters) Depth in meters obtained from the 12 kHz channel of the Knudsen bathymetry system. 5 meter depth of transducer has been applied. 3.5kHz depth ( Depth35) Format: Depth (meters) Depth in meters obtained from the Knudsen 3.5 kHz channel. 5 meter transducer depth correction has been applied. EDO speed ( EDO_knt) Edo speedlog, converted to knots millivolts * .004 = knots EDO Speedlog ( EDO) Ship speed from Edo Speedlog - millivolts Edo Depth String ( EDO_VDstr) Sea Surface Conductivity (SSCND) Falmouth Scientific TSG (OCM-S-212) sea surface conductivity (mmho/cm) Format: Conductivity -- fixed data input time interval: 15 seconds OCM sensor is mounted in the bow chamber on the suction side of the clean sea water distribution pump, approximately 5 feet from the forward facing inlet at 15 feet depth. Calibration - 01/01/2003 Sea Surface Temperature (SSTMP) Falmouth Scientific TSG (OTM-S-212) sea surface conductivity (degrees C) Format: Sea surface temperature -- fixed data input time interval: 15 seconds OTM sensor is mounted in the bow chamber on the suction side of the clean sea water distribution pump approximately 5 feet from the forward facing inlet, at 15 feet depth. Calibration - 01/01/2003 GPS course over ground (GPS_COG) Course over ground (true) obtained from NMEA GPS_VTG data sentence. Format: Course Latitude (GPS_Lat) Latitude from GPS NMEA GGA data sentence formatted for display. Format: dd mm.mmm, N/S Longitude (GPS_Lon) Longitude from GPS NMEA GGA data sentence formatted for display. Format: ddd mm.mmm, E/W GPS Navigation data (GPS) Complete NMEA data output from the primary GPS receiver. The datum used by both the P-Code and Northstar GPS receivers is WGS84. The single digit following the position information in the GPS_GGA data string indicates the type of GPS fix as follows: 0=No valid fix; 1=Standard; 2=Differential; 3=P-Code NMEA GPGGA data sentence: Header , UTC of position, Latitude, N/S, Longitude, E/W, Quality indicator, Number of satellites in use, Horizontal dilution, Altitude, M (meters), Geoidal seperation, M (meters), Age of differential data (secs), Differential reference station I.D. * checksum. (Lat & Lon values are "degrees minutes.decimal_minutes") NMEA GPVTG data sentence: Header, Course, T (degrees true), Course, M (magnetic), Speed, N (knots), Speed, K (km/hr) * checksum. GPS speed over ground (GPS_SOG) Speed over ground (knots) obtained from NMEA GPS_VTG data sentence. Format: Speed GPS type (GPS_TYPE) GPS position type (Std, Diff, P-Code) GPS position type indicator is obtained from the "quality indicator" included as part of the GPS NMEA GGA data sentence. Gyro heading (Gyro) Ship's heading (degrees true) obtained from the Gyro NMEA HEHDT data sentence. Format: Heading (degrees true) IMET Wind (IMET_WND) Format: X, Y, Total, Max, Min, LastVane, LastCompass, C1, C2 Wind X (m/sec), Positive for a stbd to port wind Wind Y (m/sec), Positive for a bow to stern wind Wind Total (m/sec), Averaged over previous minute Wind Max (m/sec, 15 sec interval), Wind Min (m/sec, 15 sec interval), Last Vane Reading (deg), Last Compass Reading (deg), Counter1 ("0"), Counter2 ("4") Note - Wind direction is not provided as a single quantity. Direction values are ship relative. The wind sensor does not have a compass installed (value should always be 0.0). Calibration - Jan 2003 IMET Air Temperature (Air_Temp) Format: Temp (C) Data is obtained from IMET_HRH primary sensor. IMET Barometric Pressure (IMET_BPR) Format: Barometric pressure (milli-bars) Calibration - Jan 2003 IMET longwave radiation ( IMET_LWR) IMET Precipation (IMET_PRC) Format: Precipitation (millimeters) Last minute (mm/min), Last hour (mm/hr), Present Level (mm) Calibration - Jan 2003 IMET relative humidity (HRH) Format: Humidity (%RH) Data is obtained from IMET_HRH primary sensor. IMET Shortwave Radiation (IMET_SWR) Format: Radiation (watts/square meter) Calibration - Jan 2003 IMET Humidity (IMET_HRH) Format: Humidity (%RH), Temperature (C) Note - IMET humidity and air temperature data are both obtained from this instrument. Calibration - Jan 2003 Knudsen bathymetry ( PKEL99) Depth data obtained from the Knudsen bathymetry system. Values have been corrected for transducer depth (5 meters). Format: Header ($PKEL99), time (hhmmss), 12 kHz depth (meters), 3.5 kHz depth (meters), Speed of sound (m/s), Lat (dd mm.mmm N/S), Lon (ddd mm.mmm E/W) MetraByte #1 ( MByte1) NMEA Gyro (HEHDT) Ship's heading obtained from the Sperry Gyro. NMEA format: Header ($HEHDT), Heading (degrees), T (true), Heading (degrees), M (magnetic) * checksum. Version 2.20 (1/1/97) of the NMEA 0183 standard does not show magnetic heading in this data sentence and the validity of this item is questionable. Position from GPS receiver (Lat_Lon) Latitude & Longitude in decimal degrees. Format: +/-dd.dddddd +/-ddd.dddddd (N & E are "+") Salinity (Salinity) Format: Salinity Salinity calculated from sea surface temperature and conductivity data values in accordance with UNESCO 44. *** calibration by science party kn166-11 showed salinity calibration off. Reading - 0.475 = salinity, with autosal salinity checks 19-29 June 2002 Sea surface fluorometer ( Fluorometer) WetLabs Wet-Star fluorometer located in the clean seawater system. Value reported in millivolts. Calibration must be done by interested science parties. Purchased & installed Jan 2003 Sound velocity ( SSV) Format: Sound_Velocity (meters/sec) Surface sound velocity calculated from sea surface temperature and conductivity data values. Intermediate salinity values are calculated in accordance with UNESCO 44. True wind direction (Wnd_Dir) Format: Wnd_dir (degrees) Wind direction obtained from the IMET wind sensor and corrected for ship heading (gyro) plus ship course and speed (GPS SOG & COG). True wind speed (Wnd_Spd) Format: Wnd_spd (meters/sec) Wind speed obtained from the IMET wind sensor and corrected for ship heading (gyro) plus ship course and speed (GPS SOG & COG). True wind speed & direction (TWind) Format: Speed, Direction (meters/sec, degrees) Wind direction is given in meteorological terms; a 0 degree wind comes from the north. Ship speed and direction of travel are obtaned from GPS data (GGA SOG & COG). Sensor mounting orientation is corrected using the direction the ship is pointing obtained from the gyro (the ship is not necessarily moving in the direction its pointing). Turner fluorometer data (TF10_data) Fluorometer data from Turner Designs Model 10. Full scale = 1 volt (1000.00 from MetraByte A/D module). Exact value is not in agreement with instrument front panel meter due to the characteristics of the calibration resistor. Science party is responsible for recording comparative readings during the cruise if needed. Turner fluorometer range (TF10_Range) Fluorometer range setting from Turner Designs Model 10 (full scale = 1 volt). Actual values reported by the MetraByte A/D module (1000.00=1 volt) are not in agreement with the value indicated in the Turner manual due to the accuracy of the calibration resistor. Actual readings are per the following table (science party should check these values at some point during the cruise): Range Expected Actual X0 0.0v 000.10 X3.16 0.4v 488.60 X10 0.7v 831.00 X31.6 1.0v 9999.99